▎ 摘　　要

This study presents an electrochemical detection system for the detection of heavy metals in soil. The electrochemical sensor exploited a disposable screen-sprinted electrode (SPE) which was modified by ionic liquid (IL) n-octylpyridinum hexafluorophosphate (OPFP) and graphene (GR) was fabricated and used for sensitive detection of Cd (II) in soil. Based on electrochemical sensor, this system was further used for sensitive detection of trace cadmium ions by square wave anodic stripping voltammetry (SWASV). We integrated electrochemical sensor and signal detection circuit to fabricate heavy metals detection instrument which generating square wave signal and realizing signal acquisition and processing. The sensor, detection instrument and upper computer together make up the detection system. These data signal got from detection instrument were sent to the upper computer with serial communication and further processed and analyzed by upper computer and then get the stripping voltammetry curve of cadmium ions. The heavy metal types and concentration could be got from the stripping peak potential and peak current value, respectively. The results of performance evaluation showed that this detection system could realize the detection of Cd (II) in soil on-site with automatic signal acquisition, processing and detection results displaying which was low-cost and timesaving, the linear response was observed in the range from 5.0 to 70.0 mu gL(-1) with a detection limit of 3 mu gL(-1).